Deep brain stimulation or thalamotomy in fragile X-associated tremor/ataxia syndrome? Case report

Abstract

We present the case of a 66-year-old man who has been treated for essential tremor since the age of 58. He developed mild cerebellar gait ataxia seven years after tremor onset. Moderate, global brain atrophy was identified on MRI scans. At the age of 68, only temporary tremor relief could be achieved by bilateral deep brain stimulation of the ventral intermedius nucleus of the thalamus. Bilateral stimulation of the subthalamic nucleus also resulted only in transient improvement. In the meantime, progressive gait ataxia and tetraataxia developed accompanied by other cerebellar symptoms, such as nystagmus and scanning speech. These correlated with progressive development of bilateral symmetric hyperintensity of the middle cerebellar peduncles on T2 weighted MRI scans. Genetic testing revealed premutation of the FMR1 gene, establishing the diagnosis of fragile X-associated tremor/ataxia syndrome. Although this is a rare disorder, it should be taken into consideration during preoperative evaluation of essential tremor. Postural tremor ceased two years later after thalamotomy on the left side, while kinetic tremor of the right hand also improved.

Deep brain stimulation in uncommon tremor disorders: indications, targets, and programming

“…Two studies reported no occurrence of AEs. Stimulation frequency varied from 125 to 185 Hz, intensity from 1.5 to 5.4 V, and pulse width from 60 to 150 sec (Table 5) [83–88]. …”

Case Report: Deep brain stimulation improves tremor in FGF-14 associated spinocerebellar ataxia

“…Here we report the first case of a SCA 27 patient with favorable tremor response to DBS of the VIM and the subthalamic fiber tracts harboring the DTT. To date, a tremor-suppressing effect of high-frequency VIM-DBS was described in SCA 2, 3, 6, 31, and FXTAS ( 11 – 25 ) ( Table 1 ). Stimulation of subthalamic projections provides the possibility of cerebellar neuromodulation by antidromic stimulation of the DTT ( 4 , 26 ).…”

Making a Difference—Positive Effect of Unilateral VIM Gamma Knife Thalamotomy in the Therapy of Tremor in Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)

“…Deterioration in certain features of the examination performed by the physiotherapist were associated with the progressive nature of FXTAS. This could also be observed during MRI, in the form of an increased signal in T2-weighted image within both hemispheres of cerebellum and bilaterally within middle cerebellar pedunculi, rather than side effects of GK thalamotomy ( 13 ). Approval of the Ethical Committee was not necessary for preparation of this article, as this work is a case study.…”

“…Non-pharmacological interventions for the treatment of FXTAS include: Deep Brain Stimulation (DBS), Gamma Knife Radiosurgery (GK), Focal Ultrasound (FUS) and Radiofrequency ( 2 – 13 ) with DBS and Radiofrequency the most popular amongst current literature ( 2 – 6 , 13 ). With respect to positive outcomes of these treatments, bilateral stimulation with DBS of the ventro-oralis posterior (VOP) thalamic nucleus and zona incerta (ZI) have been documented ( 14 ).…”